1. Field of the Invention
The present invention relates generally to data storage devices and systems, and more particularly to a data disc library apparatus utilizing multiple removable disc drives and multiple removable disc media arranged in an annular configuration.
2. Description of Related Art
A typical digital data tape cartridge handling library includes number of columns of stacked bins containing data tape cartridges positioned around a centrally located manipulating arm with a cartridge grasping hand which can rotate, translate and elevate to position the hand in front of a particular bin containing the desired cartridge.
Multiple compact audio disc (CD) and digital video disc (DVD) storage and handling apparatuses are also known. Some disc storage apparatus configurations are toroidal and some are linear stacks. Representative examples of such read only Jukebox disc changers are disclosed in U. S. Pat. Nos. 5,644,558; 5,235,579; 5,886,974; 5,307,331; 5,274,620; 4,567,584; 4,734,814; 3,008,721; and WIPO publication No. WO87/07423.
These apparatuses are all directed to the handling of discs or cartridges one at a time. This requires a substantial time period of drive inactivity while a disc is unloaded or loaded between the library storage and the drive. In the case of tape cartridge libraries, this delay is compensated for by having several drives being accessible to the manipulator apparatus. However, in the handling of digital data, especially where the reading and writing of critical data is involved, speed of access to data is important and the simultaneous handling of multiple data storage cartridges may be desirable.
In the case of optical digital media, the random access speed is currently limited typically to between 100 ms to 200 msec. However, large amounts of data can be stored on these discs such as currently up to about 17 gigabytes of data. Currently only 1 to 4 drives have been used in jukebox type CD and DVD devices and these are read only devices. Thus access speed is extremely limited for data handling purposes. Accordingly there is a strong need for an apparatus that overcomes the limitations posed by current CD and DVD access times in order to make the optical disc media suitable for data intensive operations, such as in the terabyte range, which is reliable, low cost, and compact.
It is with respect to these and other considerations that the present invention is made which utilizes conventionally available read and writable (R for WORM or RW, or RAM) CD and future DVD drives and conventional optical disc media combined into a new configuration.
The present invention is an apparatus for handling and storing a plurality of removable digital data storage modules, e.g. tape cartridges or discs. The apparatus comprises a toroidal configuration of storage locations for the discs or cartridges, a plurality of disc or cartridge drives mounted adjacent to the storage locations in a generally annular arrangement, a means for moving any disc or cartridge into and out of each selected drive on demand; and a control means for directing operation of the means for moving the discs or cartridges and controlling selection and operation of the disc drives.
More particularly, the apparatus in accordance with a preferred embodiment the present invention comprises a stationary frame, a rotating frame or xe2x80x9ccarouselxe2x80x9d mounted on the stationary frame supporting a number of data discs in a toroidal configuration for rotation about a central axis. A plurality of drives are mounted to the stationary frame in an annular configuration above the carousel. A motor is operably connected between the stationary frame and the carousel for rotation of the carousel about the central axis. Beneath each disc drive is a lift mechanism comprised of a lift finger operably extending below the carousel and a motor to raise and lower the arm. The lift mechanism operates to vertically lift a data disc positioned beneath the disc drive into an opening in the drive and receive and lower a disc ejected from the drive. A disc access port in the drive module is preferably provided for manual loading of one or more discs into the carousel. A controller is operably connected to each of the lift mechanisms and to the carousel motor which controls alignment of the carousel, and insertion and removal of the disc from any one of the disc drives in accordance with a demand schedule from a library controller. The library controller manages and coordinates the operation of the disc drives, the lift mechanisms and the operation of the carousel to cue the discs to the desired drives.
Further, a secondary rotating carousel and a secondary storage transfer mechanism is preferably provided for additional storage capacity. The secondary carousel is mounted to the stationary frame below the first, or primary, carousel and a drive motor is operably connected between the stationary frame and the secondary carousel for independent rotation of the carousel about the central axis. The secondary carousel also supports a number of data discs in a toroidal configuration for rotation about the central axis. The secondary storage disc transfer mechanism or passthrough device is fastened to the stationary frame and has a lift finger which operably moves discs between the primary and secondary carousels. The passthrough device vertically lifts a data disc and transfers it from the lower, secondary carousel to the uppers primary carousel. The library controller is operably connected to the passthrough device, the carousel motor that controls alignment of the secondary carousel, and insertion and removal of the disc from the primary carousel in accordance with a demand schedule from a library controller. The present invention is particularly applicable to the manipulation of removable media, without any caddy, or specific media protection or enclosure. It also take advantage of the standard xcfx86120 mm, 1.2 mm thick media used for CD-x and DVD-x.
These and various other features as well as advantages which characterize the present invention will be apparent from a reading of the following detailed description and a review of the associated drawings.